Future active participles are easily identified and formed. The distinctive letter sequence is -urus, -ura, -urum (they decline like bonus, -a, -um), so you can remember them by the English word "future." Like all participles, they are verbal adjectives, but they are rarely used in comparison with the present active and perfect passive (never in the ablative absolute, by the way).

Future participles are important because they are incorporated in other forms. With esse, they make the future active infinitive. With the present, imperfect, and future indicative of sum they form the "active periphrastic," an alternative to the future tense that indicates imminent action (e.g. paraturus sum = "I am about to prepare," "I am going to prepare"); with the present and imperfect subjunctive they are used in the sequence of tenses to emphasize subsequent action in a subordinate clause, relative to that of the main verb.